Add Chemistry to auto scored domains for Instructor Training Requests

This fixes carpentries#1505. Tests were adjust.

amy/extrequests/tests/test_training_request.py

@@ -148,10 +148,34 @@ def test_domains(self):
         domains = KnowledgeDomain.objects.filter(name__in=[
             'Humanities', 'Library and information science',
             'Economics/business', 'Social sciences',
+            'Chemistry',
         ])
         self.tr.domains.set(domains)
         self.assertEqual(self.tr.score_auto, 1)
 
+    def test_each_domain(self):
+        "Ensure each domain from the list counts for +1 score_auto."
+        domain_names = [
+            'Humanities',
+            'Library and information science',
+            'Economics/business',
+            'Social sciences',
+            'Chemistry',
+        ]
+
+        last_domain = None
+
+        for name in domain_names:
+            # we need to remove last domain added, but we can't use `.clear`
+            # because it doesn't trigger the m2m_changed signal
+            if last_domain:
+                self.tr.domains.remove(last_domain)
+
+            self.assertEqual(self.tr.score_auto, 0, name)
+            last_domain = KnowledgeDomain.objects.get(name=name)
+            self.tr.domains.add(last_domain)
+            self.assertEqual(self.tr.score_auto, 1, name)
+
     def test_underrepresented(self):
         """With change in https://github.com/swcarpentry/amy/issues/1468,
         we start automatically scoring underrepresented field."""

amy/workshops/models.py

@@ -1779,10 +1779,12 @@ def recalculate_score_auto(self):
         if self.underresourced:
             score += 1
 
-        # economics or social sciences, arts, humanities, or library science
+        # economics or social sciences, arts, humanities, library science, or
+        # chemistry
         scoring_domains = [
             'Humanities', 'Library and information science',
             'Economics/business', 'Social sciences',
+            'Chemistry',
         ]
         for domain in self.domains.all():
             if domain.name in scoring_domains: